Webapr 5, 2022 · the “claim disallowance” irs letter 105c or letter 106c is your legal notice that the irs is not allowing the credit or refund you claimed. What does this letter mean. Webjun 2, 2022 · the “claim disallowance” irs letter 105c or letter 106c is your legal notice that the irs is not allowing the credit or refund you claimed. Webuse the following paragraph when disallowing a request for abatement using letter 105c or letter 106c: If you disagree with our determination and want to file a…